Detection of human bocavirus in children with Kawasaki disease

Emerging evidence of microbial infection in causing systematic immune vasculitis in Kawasaki disease

Kawasaki disease (KD) is a systematic vasculitis that is often complicated by coronary artery lesions and is a leading cause of acquired heart disease in developed countries. Previous studies have suggested that genetic susceptibility, together with an inducing infectious agent, could be involved in KD pathogenesis; however, the precise causative agent of this disease remains unknown. Moreover, there are still debates concerning whether KD is an infectious disease or an autoimmune disease, although many studies have begun to show that various pathogens functioning as critical inducers could activate different kinds of immune cells, consequently leading to the dysfunction of endothelial cells and systematic vasculitis. Here in this review, we attempt to summarize all the available evidence concerning pathogen infections associated with KD pathogenesis. We also discuss the related mechanisms, present a future perspective, and identify the open questions that remain to be investigated, thereby providing a comprehensive description of pathogen infections and their correlations with the host immune system in leading to KD.

Autoptic Findings in Cases of Sudden Death Due to Kawasaki Disease

Kawasaki disease (KD) is the second-most-common childhood vasculitis, and its etiology is still unknown today. Even though the acute illness is usually self-limiting, sometimes, it can generate complications, such as coronary artery aneurysms (CAA), acute myocardial infarction (AMI), heart failure, or arrhythmias, and can rarely cause sudden or unexpected deaths. We present a review of the literature, which collects autoptic and histopathological data relating to many of the cases of these deaths. On the basis of the titles and abstracts, we selected 54 scientific publications for a total of 117 cases. Among them, as expected, the majority of the deaths were due to AMI (41.03%), arrhythmia (8.55%), acute coronary syndrome (8.55%), and CAA rupture (11.97%), involving mostly 20-year-olds or younger individuls (69.23%). This is not surprising since the CAs are the most involved arteries. Gross autoptic and histopathological findings are reported in the paper. Our work revealed that, when compared with the incidence of KD, only a few cases suffered from sudden death, underwent an autoptic examination, and were then described in the literature. We suggest that researchers should perform autopsies to gain a better understanding of the molecular pathways involved in KD so as to propose further innovative therapeutic protocols or implement more appropriate prevention schemes.

Research trends on causes of Kawasaki disease in the COVID-19 era: focus on viral infections

Despite studies on the etiology of Kawasaki disease (KD) ongoing for half a century since its discovery, its cause has not yet been clearly identified. Although the clinical, epidemiological, and pathophysiological characteristics of KD are presumed to be closely related to infectious diseases, studies of various pathogens to identify its etiology have been actively conducted. To date, bacteria, fungi, and viruses have been investigated to determine the relationship between KD and infection, among which viruses have attracted the most attention. In particular, during the coronavirus disease 2019 pandemic, there were many reports in Europe of a sharp increase in cases of Kawasaki-like disease (KLD), while conflicting reports that the prevalence of KD decreased due to thorough "social distancing" or "wearing mask" in Asian countries drew more attention regarding the association between KD and viral infection. Therefore, the differential diagnosis of KD from KLD with these similar spectra has become a very important issue; simultaneously, research to solve questions about the association between KD and viral infections, including sudden acute respiratory syndrome coronavirus 2, is drawing attention again. Moreover, a new concept has emerged that immune responses occurring in patients with KD can be caused by the pathogen itself as well as host cells damaged by infection. This paper summarizes the research trends into KD etiology and related pathophysiology, especially its association with viral infections, and present future research tasks to increase our understanding of KD.

A meta-analysis on association between viral infections and Kawasaki disease in children

Aim: To investigate the association between different viral infections and the development of Kawasaki disease (KD) in children. Materials & methods: Electronic databases were searched for relevant studies published from inception to May 2020. The pooled odds ratios (ORs) of the association of different viral pathogens with KD were estimated using a random-effects model weighted by the inverse variance method. Results: The strongest associations were found between KD and human parvovirus B19 viremia (OR = 41.05; 95% CI: 5.13–328.28; I-square = 0%), EBV IgM seropositivity (OR = 7.18; 95% CI: 3.65–14.12, I-square = 0%) and human herpesvirus-6 IgG seropositivity (OR = 5.83; 95% CI: 1.06–32.01). Conclusion: Human parvovirus B19, EBV and human herpesvirus-6 are highly suspected to be key contributors to the development of KD.

The wide spectrum of Kawasaki-like disease associated with SARS-CoV-2 infection

Introduction: On June 2020, the first case of concurrent Covid-19 and Kawasaki disease (KD) was published. After this first description, further works reported new cases of children affected by KD and KD-like syndrome after SARS-CoV-2 infection. The clinical and biochemical features of these patients differed from the historical cohorts of KD, suggesting the possibility of a new multi-systemic inflammatory syndrome. Is still unclear if this new clinical entity, often referred as pediatric inflammatory multisystem syndrome (PIMS) or multi-system inflammatory syndrome in children (MIS-C), could be considered as part of the KD spectrum or is a new disease with different pathogenic mechanisms and uniquely linked to SARS-CoV-2 infection. The authors searched the available literature in MedLine (via Pubmed) with the terms ('coronaviruses' OR 'coronavirus') AND ('Kawasaki disease') for English studies without any temporal limit. Areas covered: This review aims to comprehensively describe multisystem inflammatory syndromes affecting children during Coronaviruses outbreak, and to evaluate the possible pathogenic role of human Coronaviridae in KD and KD-like syndromes. Expert opinion: An increased incidence of PIMS-TS, during the Covid-19 pandemic has been reported, suggesting that SARS-CoV-2 may trigger a severe hyper-inflammatory syndrome in childhood. The pathophysiological mechanisms of this disease are still unclear. Based on these findings, SARS-CoV-2 may be considered another trigger in the complex mosaic about the relationship among infectious agents and the occurrence of systemic hyper-inflammation related syndromes.

Kawasaki Disease as the Immune-Mediated Echo of a Viral Infection

Although the etiology of Kawasaki disease (KD) remains elusive, the available evidence indicates that the primum movens may be a dysregulated immune response to various microbial agents, leading to cytokine cascade and endothelial cell activation in patients with KD. Documented infections by different viruses in many individual cases have been largely reported and are discussed herein, but attempts to demonstrate their causative role in the distinctive KD scenario and KD epidemiological features have been disappointing. To date, no definite link has been irrefutably found between a single infection and KD.

Infectious triggers for vasculitis

PURPOSE OF REVIEW

Infections have been suggested to contribute to disease induction and reactivation in many of the idiopathic vasculitides. This review describes and evaluates the evidence that microbes are involved in the etiopathogenesis of these diseases.

RECENT FINDINGS

Large-vessel vasculitis has recently been associated with two specific bacteria. Mycobacterium tuberculosis is thought to have an inducing role in Takayasu arteritis and a Burkholderia bacterium might be involved in giant cell arteritis. Hepatitis B and C viruses have been linked to polyarteritis nodosa. In antineutrophil cytoplasmic autoantibody-associated vasculitis, and more specifically granulomatosis with polyangiitis (GPA), Staphylococcus aureus has been the focus of many studies. Chronic nasal carriage of S. aureus is related to endonasal activity and disease relapses in GPA patients. Moreover, antibacterial treatment is known to reduce the risk for disease relapses. If and how pathogens trigger vasculitis is still unclear, but several potential mechanisms have been suggested and are briefly reviewed here.

SUMMARY

Although many observations suggest a link between infections and the development of vasculitis, no direct proof exists. Transcriptomic and proteomic studies of the pathogens involved could aid in identifying specific or common traits of pathogens that are relevant for the development and reactivation of vasculitis.

'Human bocavirus in Pakistani children with gastroenteritis'

Human Bocaviruses (HBoV) have been detected in human respiratory and gastrointestinal infections worldwide. Four genotypes of HBoV (HBoV1-4) have been described; HBoV-1 is associated with respiratory tract infections while HBoV-2, -3, and -4 genotypes are considered as entero-pathogenic although the exact role largely remains unclear. The global prevalence of HBoV has been reported, but the epidemiological data from Pakistan is largely unavailable to date. This study was conducted to understand the genetic diversity and disease prevalence of HBoV in hospitalized Pakistani children with acute diarrhea. During 2009, a total of 365 stool samples were collected from children hospitalized with gastrointestinal symptoms (as per WHO case definitions) at Rawalpindi General Hospital, Pakistan. Demographic and clinical data were recorded using a standardized questionnaire. The samples were tested for HBoV and rotavirus using real-time RT-PCR and ELISA, respectively. There were 47 (13%) samples positive for HBoV with 98% (n = 46) showing co-infection with rotavirus. HBoV-1 was the most frequently detected and was found in 94% samples followed by HBoV-2 and HBoV-3 genotypes. The mean age of infected children was 7.57 ± 5.4 months while detection was more frequent in males (n = 32, 68%). All cases recovered after 2.43 ± 1.0 mean days of treatment. On phylogenetic analysis, HBoV strains from Pakistan clustered closely with viruses from neighboring Bangladesh and China. These findings represent the first known epidemiological study in Pakistan to investigate the role of HBoV in acute gastroenteritis. The clinical data demonstrates that HBoV is not significantly associated with gastroenteritis alone and predominantly co-infections with rotavirus are found.

Markers of a recent bocavirus infection in children with Kawasaki disease: "a year prospective study"

BACKGROUND

Retrospective studies and case-reports have suggested the possible role of various viruses in the pathogenesis of the Kawasaki disease.

OBJECTIVES

To determine prospectively the incidence of Kawasaki diseases associated with a recent bocavirus infection in the course of a year.

STUDY DESIGN

Thirty-two children with Kawasaki disease were enrolled in a 13 months prospective study to assess the frequency of human bocavirus type 1 infections. Seasonal shedding of virus, markers of recent infection such as viraemia, viral load, and serum interferon alpha were analyzed.

RESULTS

Three of 32 (9%) children had HBoV-DNA in the serum suggesting a recent infection. HBoV-DNA was detected in naso-pharyngeal aspiration of 7/32 (21.8%) children with Kawasaki Disease and six of them (18%) had an increased viral load. No common respiratory viruses were isolated from the 32 patients with the exception of one adenovirus. The seven bocaviruses were identified during the winter-spring season. In addition, 4 of 7 of Kawasaki disease patients shedding bocavirus had detectable interferon alpha in the blood, indicating a possible active or recent viral infection.

CONCLUSIONS

This study shows that a recent bocavirus infection is concomitant with the onset of some cases of Kawasaki disease. Bocavirus may be a cofactor in the pathogenesis of this disease as previously reported for other infectious agents.

Evaluation of the Temporal Association between Kawasaki Disease and Viral Infections in South Korea

Background and Objectives

This study is aimed at elucidating potential temporal associations between the occurrence of Kawasaki disease (KD) and various viral infections.

Subjects and Methods

We obtained monthly patterns of KD from the seventh nationwide survey and viral detection data from the Korea Centers for Disease Control and Prevention from 2009 to 2011 and evaluated temporal correlations between them for each month. The respiratory viruses detected using a multiplex real-time-polymerase chain reaction kit were influenza virus (A/H1N1, A/H3N2, A/H5N1, and B), adenovirus, parainfluenza virus (type 1, 2, 3), respiratory syncytial virus (type A, B), human rhinovirus, human coronavirus (OC43/229E, NL63), human bocavirus, and enterovirus.

Results

We obtained data from a total of 13031 patients who were treated for acute KD from 87 hospitals with pediatric residence programs. During this survey, KD showed highest overall incidence in summer and winter seasons and lowest incidence in February and October. We received viral detection data for a total of 14267 patients. Viral detection was highest during winter and spring seasons. The most commonly detected virus was human rhinovirus (32.6%), followed by influenza virus (26.8%). The monthly incidence of KD showed significant correlation with the monthly overall viral detection (p=0.022, r=0.382). In particular, human bocavirus and enterovirus have significant correlations with monthly patterns of KD occurrence (p=0.032 and p=0.007, respectively) and influenza virus correlated with KD occurrence with borderline significance (p=0.063).

Conclusion

The temporal association between monthly occurrence of KD and viral detection suggests the etiologic importance of precedent infection in the development of KD.

Possible involvement of infection with human coronavirus 229E, but not NL63, in Kawasaki disease

Although human coronavirus (HCoV)‐NL63 was once considered a possible causative agent of Kawasaki disease based on RT‐PCR analyses, subsequent studies could not confirm the result. In this study, this possibility was explored using serological tests. To evaluate the role of HCoV infection in patients with Kawasaki disease, immunofluorescence assays and virus neutralizing tests were performed. Paired serum samples were obtained from patients with Kawasaki disease who had not been treated with γ‐globulin. HCoV‐NL63 and two antigenically different isolates of HCoV‐229E (ATCC‐VR740 and a new isolate, Sendai‐H) were examined as controls. Immunofluorescence assays detected no difference in HCoV‐NL63 antibody positivity between the patients with Kawasaki disease and controls, whereas the rate of HCoV‐229E antibody positivity was higher in the patients with Kawasaki disease than that in controls. The neutralizing tests revealed no difference in seropositivity between the acute and recovery phases of patients with Kawasaki disease for the two HCoV‐229Es. However, the Kawasaki disease specimens obtained from patients in recovery phase displayed significantly higher positivity for Sendai‐H, but not for ATCC‐VR740, as compared to the controls. The serological test supported no involvement of HCoV‐NL63 but suggested the possible involvement of HCoV‐229E in the development of Kawasaki disease. J. Med. Virol. 86:2146–2153, 2014. © 2014 Wiley Periodicals, Inc.

The role of infection in Kawasaki syndrome

Objectives

To analyse the evidence suggesting a possible infectious origin of Kawasaki syndrome (KS).

Methods

PubMed was searched for all of the studies published over the last 15 years using the key words “Kawasaki syndrome” or “mucocutaneous lymph node syndrome” and “infectious disease” or “genetics” or “vasculitis” or “pathogenesis”.

Results

Various levels of evidence support the hypothesis that KS is a complex disease triggered by an infection due to one or more pathogens. Viruses or bacteria may be the primum movens, although no specific infectious agent can be considered definitely etiological. A number of genetic polymorphisms have been identified in subjects with KS, but none of them can currently be considered a real marker of susceptibility.

Conclusions

Various data suggest that KS is intimately related to infectious diseases and that its clinical expression is influenced by predisposing genetic backgrounds, but our knowledge of the infectious agent(s) involved and the genetic characteristics of susceptible children remains only partial. Further studies are needed to address the many still open questions concerning the disease.

Human bocavirus-the first 5 years

Four species of human bocavirus (HBoV) have been recently discovered and classified in the Bocavirus genus (family Parvoviridae, subfamily Parvovirinae). Although detected both in respiratory and stool samples worldwide, HBoV1 is predominantly a respiratory pathogen, whereas HBoV2, HBoV3, and HBoV4 have been found mainly in stool. A variety of signs and symptoms have been described in patients with HBoV infection including rhinitis, pharyngitis, cough, dyspnea, wheezing, pneumonia, acute otitis media, fever, nausea, vomiting, and diarrhea. Many of these potential manifestations have not been systematically explored, and they have been questioned because of high HBoV co-infection rates in symptomatic subjects and high HBoV detection rates in asymptomatic subjects. However, evidence is mounting to show that HBoV1 is an important cause of lower respiratory tract illness. The best currently available diagnostic approaches are quantitative PCR and serology. This concise review summarizes the current clinical knowledge on HBoV species.

Human bocavirus as an important cause of respiratory tract infection in Taiwanese children

BACKGROUND

Human bocavirus (HBoV), first described in September 2005, was considered a causative agent of previously unexplained respiratory tract diseases. However, only few reports provide the evidence for an association between HBoV and respiratory tract diseases. We conducted a prospective clinical and molecular study of HBoV in Taiwan.

METHODS

We enrolled 705 children who visited our outpatient pediatric clinics in a medical center because of symptoms and signs of respiratory tract infections from November 2008 to October 2009. Throat swab was performed and HBoV polymerase chain reaction and viral culture were done simultaneously.

RESULTS

Positive viral results were confirmed in 159 (22.6%) of the 705 children. HBoV was found in 35 samples and it was supposed to be as a single virus in 32 samples because viral isolation of these 32 samples did not identify other virus. The other three patients had coinfection with another virus. One child got HBoV reinfection 6 months after the first infection. Seventy-one percentage of these HBoV infections occurred between November and March. Of the 34 children with positive HBoV, 26 (76%) patients were younger than 5 years; their common symptoms were cough, rhinorrhea, and fever; the most common diagnoses were bronchitis (34%, 12/35) and sinusitis (31%, 11/35) followed by pharyngitis (29%, 10/35) and asthma exacerbation (26%, 9/35). Three of the 34 patients needed hospitalization.

CONCLUSION

HBoV is an emerging human parvovirus that may cause respiratory tract infection in young children. Diseases associated with HBoV may range from pharyngitis, sinusitis, acute otitis media to bronchitis, asthma, and even pneumonia.

Kawasaki disease and human bocavirus--potential association?

Kawasaki disease (KD) is an acute febrile multisystem vasculitic syndrome of unknown etiology, occurring mostly in infants and children younger than 5 years of age. We present a 13-month-old male with KD from whom was found human bocavirus DNA in nasopharyngeal secretions. Human bocavirus DNA in a patient with KD raised question about the coincidental or possible etiological association.

Myocardial infarction in a 35-day-old infant with incomplete Kawasaki disease and chicken pox

Kawasaki disease is an acute febrile vasculitis of infancy and early childhood. It is uncommon in early infancy, because a significant proportion of these children do not meet the classical diagnostic criteria at this age. Infants younger than 6 months with persistent fever and some of the criteria of Kawasaki disease should always raise suspicion for Kawasaki disease early to avoid delayed diagnosis with severe cardiac complications. We present a 35-day-old infant with incomplete Kawasaki disease complicated with myocardial infarction during chicken pox.

Review of new and newly discovered respiratory tract viruses in children

Respiratory tract viral infection continues to be among the most common reasons for emergency department visits and hospitalization of children, particularly infants younger than 1 year, in the United States. Throughout the years, clinicians have considered respiratory syncytial virus followed by influenza as the most common pathogens responsible. Over the past decade, new viruses have been discovered through both more specific testing and the finding of new agents causing infection. This includes human metapneumovirus, which leads to similar but often epidemiologically more severe clinical symptoms than respiratory syncytial virus. Other agents responsible for lower respiratory tract infection include Coronavirus (severe acute respiratory syndrome), Bocavirus, and others. This review serves to focus on some of the recent literature on these agents and the clinical impact they have on pediatric lung infection.

[Human bocavirus infections]

Le bocavirus humain (HboV) a été récemment cloné lors d’un criblage systématique de prélèvements nasopharyngés d’enfants hospitalisés pour infections respiratoires. Ce virus, du genre bocavirus, de la famille des Parvoviridae, a été détecté par son ADN, lors de différentes études, dans environ 5 % des prélèvements nasopharyngés. Il serait responsable d’infections respiratoires hautes et basses chez les jeunes enfant de moins de cinq ans avec un pic hivernal. Son rôle pathogène dans ces infections reste encore à déterminer, compte tenu d’un taux élevé de co-infections virales. Des études supplémentaires permettront de préciser le rôle de ce virus, possiblement systémique, dans d’autres affections.

Clinical and epidemiological aspects of human bocavirus infection

Human bocavirus was recently described as a novel member of the Parvoviridae to infect humans. Based on accumulating clinical and epidemiological data the virus is currently being associated with respiratory infections in young children and infants and is furthermore discussed as causative agent of gastrointestinal illness.

Searching for the cause of Kawasaki disease--cytoplasmic inclusion bodies provide new insight

Although Kawasaki disease (KD) is the most common cause of acquired heart disease in children in the developed world, its aetiology remains unknown. In this Opinion, Anne Rowley and colleagues discuss evidence, including recently identified cytoplasmic inclusion bodies, which suggests that KD is caused by an infectious agent.

Kawasaki disease (KD) has emerged as the most common cause of acquired heart disease in children in the developed world. The cause of KD remains unknown, although an as-yet unidentified infectious agent might be responsible. By determining the causative agent, we can improve diagnosis, therapy and prevention of KD. Recently, identification of an antigen-driven IgA response that was directed at cytoplasmic inclusion bodies in KD tissues has provided new insights that could unlock the mysteries of KD.